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Flow Volume (flow + volume)
Kinds of Flow Volume Selected AbstractsAutomated Volumetric Flow Quantification Using Angle-Corrected Color Doppler ImageECHOCARDIOGRAPHY, Issue 5 2004Beomjin Kim Ph.D. We have developed a fully automated method for measuring volumetric blood flow with angle-corrected blood velocity from a color Doppler image. By computing the blood flow vector through a conduit, the angle of incidence between the direction of ultrasound beam and the direction of blood flow can be measured to correct the underestimated blood velocity. This correction immediately contributes to the improvement of measurement accuracy. The developed method also enhances the conduit identification procedure that is one of the most important factors affecting the accuracy of volumetric measurement. To evaluate the validity of the developed algorithm, experimental studies had been applied to 21 healthy subjects and 10 patients. Volumetric flows were measured from a color Doppler image of the left ventricular outflow track, which were compared with blood volumes that were measured by traditional pulsed-wave (PW)-Doppler technique. The mean stroke volume difference between two methods was ,0.45 ± 11.7 (mean ± SD). The proposed algorithm is a viable method for determining blood flow volume in an automated fashion. (ECHOCARDIOGRAPHY, Volume 21, July 2004) [source] Color Doppler sonographic evaluation of flow volume of the internal carotid and vertebral arteries after carotid endarterectomyJOURNAL OF CLINICAL ULTRASOUND, Issue 5 2010Anka Mitrasinovic MD Abstract Background. To measure by Doppler sonography the blood flow volume (BFV) of the ipsilateral and contralateral extracranial internal carotid arteries (ICAs) and both vertebral arteries (VAs) before and after a carotid endarterectomy (CEA) of the ICA. We correlated the result with the degree of stenosis of the ICA. Method. One hundred seven patients who had a CEA were divided into 2 groups. Group I consisted of subjects with stenosis of ipsilateral ICA of ,70% to near occlusion and Group II included subjects with near occlusion. The Doppler sonographic examinations were performed 1 day before the CEA, 7 days after the CEA, and 1 month after the CEA. The peak systolic velocity, end-diastolic velocity, time-averaged maximum blood flow velocity, resistance index of the ipsilateral ICA, and the BFV of both ICAs and both VAs were calculated. Result. There was a significant increase in the peak systolic velocity, maximum blood flow velocity, and the BFV of the ipsilateral ICA after the CEA. The BFV of the contralateral ICA and both VAs were not significantly altered after the CEA in both groups. Conclusion. The main CEA hemodynamic effect was an increase in the BFV of the ipsilateral ICA regardless of the degree of stenosis. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound, 2010 [source] Doppler sonography of the superior mesenteric artery in children with recurrent abdominal painJOURNAL OF CLINICAL ULTRASOUND, Issue 6 2008Asli Koktener MD Abstract Purpose. Abdominal pain is one of the most common conditions in childhood and adolescence. The aim of this study was to evaluate the superior mesenteric artery (SMA) Doppler findings in children with recurrent abdominal pain. Method. Duplex Doppler sonographic measurements were performed in 20 patients with recurrent abdominal pain and in 34 controls. Results. The mean blood flow velocities, blood flow volume, and diameter of the SMA were significantly lower in patients with recurrent abdominal pain than in controls. Conclusion. Insufficient development and/or vasoconstriction of the SMA vascular bed may be involved in recurrent abdominal pain, but further studies on larger groups are needed to test this hypothesis. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008. [source] Magnetic resonance images of the globus pallidus in patients with idiopathic portal hypertension: A quantitative analysis of the relationship between signal intensity and the grade of portosystemic shuntJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2006Takeshi Fukuzawa Abstract Background and Aim:, To elucidate a quantitative relationship between hyperintensity of the globus pallidus on T1-weighted magnetic resonance images (MRI) and portosystemic shunt (PSS) in portal hypertension. Methods:, Fifteen patients with idiopathic portal hypertension (IPH) and 44 patients with liver cirrhosis (LC) underwent brain MRI to asses signal intensity at the globus pallidus and Doppler sonography to examine the blood flow volume of PSS. Blood manganese (Mn) levels were examined in 36 patients and neuropsychological tests were performed in 15 patients without overt hepatic encephalopathy. Results:, Pallidal hyperintensity on MRI was more prominent in patients with IPH than in patients with LC. There was no correlation between MRI pallidal hyperintensity and the severity of liver dysfunction or hepatic encephalopathy. The grade of hyperintensity correlated well with the grade of PSS. The correlation was stronger in patients with IPH than in patients with LC. The plasma ammonia level and whole blood Mn level significantly correlated with MRI pallidal hyperintensity, but blood Mn level showed a stronger correlation than plasma ammonia. Conclusion:, Hyperintensity of the globus pallidus on T1-weighted MRI correlated with the development of PSS independent of liver cell function. This brain image should be an index of the grade of PSS rather than a landmark of chronic liver failure. [source] Functional morphology and patterns of blood flow in the heart of Python regius,JOURNAL OF MORPHOLOGY, Issue 6 2009J. Matthias Starck Abstract Brightness-modulated ultrasonography, continuous-wave Doppler, and pulsed-wave Doppler-echocardiography were used to analyze the functional morphology of the undisturbed heart of ball pythons. In particular, the action of the muscular ridge and the atrio-ventricular valves are key features to understand how patterns of blood flow emerge from structures directing blood into the various chambers of the heart. A step-by-step image analysis of echocardiographs shows that during ventricular diastole, the atrio-ventricular valves block the interventricular canals so that blood from the right atrium first fills the cavum venosum, and blood from the left atrium fills the cavum arteriosum. During diastole, blood from the cavum venosum crosses the muscular ridge into the cavum pulmonale. During middle to late systole the muscular ridge closes, thus prohibiting further blood flow into the cavum pulmonale. At the same time, the atrio-ventricular valves open the interventricular canal and allow blood from the cavum arteriosum to flow into the cavum venosum. In the late phase of ventricular systole, all blood from the cavum pulmonale is pressed into the pulmonary trunk; all blood from the cavum venosum is pressed into both aortas. Quantitative measures of blood flow volume showed that resting snakes bypass the pulmonary circulation and shunt about twice the blood volume into the systemic circulation as into the pulmonary circulation. When digesting, the oxygen demand of snakes increased tremendously. This is associated with shunting more blood into the pulmonary circulation. The results of this study allow the presentation of a detailed functional model of the python heart. They are also the basis for a functional hypothesis of how shunting is achieved. Further, it was shown that shunting is an active regulation process in response to changing demands of the organism (here, oxygen demand). Finally, the results of this study support earlier reports about a dual pressure circulation in Python regius. J. Morphol., 2009. © 2008 Wiley-Liss, Inc. [source] Relationship between water flow volume and in-lake total phosphorus concentrations via dissolved oxygen concentrations and temperature in a warm temperate reservoir: Implications by path analysisLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 2 2006lhami Tüzün Abstract The effects of water inflow,outflow volumes on the in-lake total phosphorus (TP) concentrations was investigated for the deep, stratified Çubuk II Dam Lake. The fluctuations in the TP concentrations followed a seasonal pattern, with lower values found during the summer, and peak values during wet seasons. Both the seasonal pattern and the horizontal/vertical heterogeneities in the TP concentrations were usually found to be in accordance with those of the water flow parameters. The vertical differences in the TP concentrations provided evidence that an interflow formed at the 5 m and 10 m depths by the water inflow resulted in higher mean TP concentrations at these depths. In contrast, the water outflows had a reducing effect on the TP concentrations, particularly at the 15 m depth, by promoting net TP export. Although the horizontal distribution of the TP concentrations differed slightly between the riverine, transition and lacustrine zones, the differences did not indicate any statistical significance (P > 0.05, multivariate analysis of variance). The path analysis performed on the vertical data proved to be a promising tool in estimating the direct correlations between water flow dynamics and TP concentrations when the decomposition of indirect correlations via dissolved oxygen concentrations and temperature was accounted for in these mutual associations. [source] Decreased portal flow volume increases the area of necrosis caused by radio frequency ablation in pigsLIVER INTERNATIONAL, Issue 3 2007Tsuyoshi Yoshimoto Abstract Background/aims: Although radio frequency ablation (RFA) has been widely accepted as an effective treatment for hepatocellular carcinoma (HCC), severe complications are not uncommon. Major complications seem to occur as a result of over-ablation beyond the intended area. As most patients with HCC have underlying cirrhosis, we speculated that decreased portal flow might cause the necrosis associated with RFA. To confirm this hypothesis, we examined the area of necrosis resulting from RFA under varying conditions of portal flow in a porcine model. Methods: RFA was performed using ultrasonographic guidance in anesthetized pigs. During the RFA procedure, portal flow was regulated by a balloon catheter, which was set in a portal trunk. The necrosis area was measured after sacrifice and was compared with the hyperechoic area that appeared during ablation. In another session, RFA was performed close to the hepatic vein and endothelial damage was examined. Results: The necrosis area caused by RFA was significantly larger when the portal flow volume was decreased by 50% or more. The hyperechoic lesion was always larger than the area of pathological necrosis regardless of portal flow volume. Under conditions of decreased portal flow, the vessel endothelium near the ablated area was more readily damaged. Conclusion: Decreased portal flow volume resulted in enlargement of the area of necrosis caused by RFA. Our results indicate that over-ablation could easily occur in patients with advanced cirrhosis, and that this could lead to major complications. Ultrasonographic guidance may be helpful for avoiding over-ablation. [source] Risk factors of bronchial hyperresponsiveness in children with wheezing-associated respiratory infectionPEDIATRIC PULMONOLOGY, Issue 1 2005Sitthivuddhi Futrakul MD Abstract The objectives of this study were to identify possible risk factors of bronchial hyperesponsiveness (BHR) in children up to 5 years of age with wheezing-associated respiratory infection (WARI), and to study the prevalence of BHR. Children up to 5 years of age with WARI were enrolled in the study. The parents or caregivers of children were asked about their demographic data and clinical histories. Physical examination and clinical score assessment were performed. Pulmonary function tests, i.e., tidal breathing flow volume (TBFV), were performed to measure tidal breathing parameters before and after salbutamol nebulization. If volume at peak tidal expiratory flow/expiratory tidal volume and time to peak expiratory flow/total expiratory time increased ,20%, or tidal expiratory flow at 25% of tidal volume/peak tidal expiratory flow increased ,20% after nebulization therapy, BHR was diagnosed. The number in the positive BHR group was used to calculate the prevalence of BHR, and clinical features were compared with those of the negative BHR group. Categorical data were analyzed for statistical significance (P,<,0.05) by chi-square test or Fisher's exact test, or Student's t -test, as appropriate. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for those with statistical significance. One hundred and six wheezing children underwent pulmonary function tests before and after salbutamol nebulization. With the aforementioned criteria, 41 cases (38.7%) were diagnosed with BHR. History of reactive airway disease, (OR, 6.31; 95% CI, 1.68,25), maternal history of asthma (OR, 3.45; 95% CI, 1.34,9), breastfeeding less than 3 months (OR, 3.18; 95% CI, 1.26,8.12), and passive smoking (OR, 3; 95% CI, 1.15,7.62) were significant risk factors of BHR. The eosinophil count was significantly higher in the BHR (+) group particularly, in children 1,5 years of age (P,,,0.01). Patchy infiltrates were more commonly found in patients with negative BHR but not statistically significant. In conclusion, a history of reactive airway disease, maternal history, breastfeeding less than 3 months, and passive smoking were significant risk factors for BHR. Pediatr Pulmonol. © 2005 Wiley-Liss, Inc. [source] Cardiocirculatory effects of patent ductus arteriosus in extremely low-birth-weight infants with respiratory distress syndromePEDIATRICS INTERNATIONAL, Issue 3 2003Senji Shimada Abstract Background:,Cardiocirculatory effects of hemodynamically significant patent ductus arteriosus (hsPDA) have not been systematically studied in extremely low-birth-weight (ELBW) infants with respiratory distress syndrome (RDS). The objective of the present study was to evaluate the effects of hsPDA on the left ventricular output (LVO) and organ blood flows in ELBW infants with RDS. Methods:,Extremely low-birth-weight infants (birth-weight <1000 g) treated with surfactant for RDS were studied by serial Doppler flow examinations. Doppler flow variables in 19 infants in whom hsPDA developed (hsPDA group) were compared with those in 19 infants without hsPDA matched for gestational age, birth-weight, and postnatal age (non-hsPDA group). All infants in the hsPDA group had pharmacologic closure of ductus arteriosus when hsPDA developed. Results:,Before pharmacological closure of PDA, the hsPDA group had significantly higher LVO, lower blood flow volume of the abdominal aorta, and lower mean blood flow velocities in the celiac artery, superior mesenteric artery, and renal artery than the non-hsPDA group. These alterations in the hsPDA group reverted to the levels in the non-hsPDA group after the closure of PDA and had no deleterious effects on the cardiorespiratory status. No significant differences between the groups were found in mean blood flow velocities of the anterior cerebral artery throughout the study period. Conclusion:,These results indicate that although LVO is increased, the splanchnic and renal blood flows are decreased when hsPDA develops in ELBW infants with RDS. The effects of these alterations of LVO and organ blood flows on the cardiorespiratory course seem to be minor when early pharmacologic closure of PDA is done. [source] Local heat-shock priming-induced improvement in microvascular perfusion in osteomyocutaneous flaps is mediated by heat-shock protein 32BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2001Dr M. Rücker Background: Stress conditioning is thought to improve microvascular free flap survival but the mechanisms of protection are not clear. The aim of this study was to determine whether local induction of heat-shock protein (HSP) 32 improves microvascular perfusion in transferred osteomyocutaneous flaps. Methods: The hindlimb harvest region of osteomyocutaneous flaps in Wistar rats was subjected to stress conditioning by local heating (30 min, 42·5°C) 24 h before microvascular flap transfer. In a second group of animals, after heat-shock priming, the action of HSP-32 was inhibited by tin protoporphyrin IX. Animals with unconditioned flaps served as controls. After transfer, the microcirculation of the muscle, cutaneous, subcutaneous and periosteal tissue of the flap was analysed quantitatively for 6 h using intravital fluorescence microscopy. Results: Immunohistochemistry revealed that HSP-32 was detectable only after priming and not in unconditioned flaps. Priming did not alter functional capillary density or capillary red blood cell velocity compared with that in unconditioned flaps. However, heat-shock priming induced significant capillary dilatation (P < 0·05) and thus a substantial increase in capillary blood flow volume (P < 0·05) in all tissues of the transferred flaps. Inhibition of HSP-32 by tin protoporphyrin IX completely abolished the priming-induced improvement in capillary perfusion, as indicated by the lack of increased capillary diameters and volumetric blood flow. Conclusion: The present study demonstrated that stress conditioning by local heat-shock priming improves nutritive perfusion in osteomyocutaneous flaps by capillary dilatation, probably mediated through the vasoactive action of HSP-32. © 2001 British Journal of Surgery Society Ltd [source] 4144: Retinal blood vessel phenotyping in miceACTA OPHTHALMOLOGICA, Issue 2010J RUBERTE Purpose In the retina there is a compromise between optimal visual function and optimal oxygenation. Retinal blood vessels have a relative sparse distribution and their size is small in order to minimise optical interference with the light path. Hence, the blood flow volume in the retina is relatively low. This fact, together with the high oxygen consumption of the retinal tissue, could facilitate the development of retinal hypoxia and subsequent retinopathy when the vascular bed is altered. Thus, the analysis of retinal blood vessel must be a crucial step during retinal phenotyping in mutant mice. Methods Different technologies and methods have been used in order to analyze structure, distribution and function of retinal blood vessels, among others: retinal digest preparations, retinal whole mount immunohistochemistry, transmission and scanning electron microscopy, fluorescein and Mercox vascular injections and scanner laser ophthalmoscopy. Results In our laboratory, morphological and topographic alterations of retinal blood vessels in Bmi1 and Sirt1 knockout mice, as well as in IGF-1 and IL-10 transgenic mice, have been observed and documented Conclusion The mouse genome is fully sequenced. 99% of the coding genes present in man are also present in mouse. Moreover, the majority of disease-related genes have been conserved since the emergence of the bony fishes about 400 million years ago. These facts and the development during the last two decades of an extensive toolbox to study the functional effects of genetic variation in mice, make them the ideal model organism for the study of human eye diseases. In this sense, morphological and functional analyses of retinal blood vessel in mutant mice could help to understand vascular gene-based mechanisms that lead to retinopathy [source] Massive ascites after living donor liver transplantation with a right lobe graft larger than 0.8% of the recipient's body weightCLINICAL TRANSPLANTATION, Issue 4 2010Yasumasa Shirouzu Shirouzu Y, Ohya Y, Suda H, Asonuma K, Inomata Y. Massive ascites after living donor liver transplantation with a right lobe graft larger than 0.8% of the recipient's body weight. Clin Transplant 2010: 24: 520,527. © 2009 John Wiley & Sons A/S. Abstract:, Background:, There are only limited data on post-transplant ascites unrelated to small-sized grafts in living donor liver transplantation (LDLT). Methods:, The subjects were 59 adult patients who had received right lobe LDLT with a graft weight-to-recipient weight ratio (GRWR) > 0.8%. Patients were divided into either Group 1 (n = 14, massive ascites, defined as the production of ascitic fluid > 1000 mL/d that lasted longer than 14 d after LDLT) or Group 2 (n = 45, no development of massive ascites). Patients were followed for a median period of 3.0 yr (range, 0.5,7.5 yr). Results:, Group 1 had both higher Model for End-Stage Liver Disease score and Child-Pugh score than Group 2. Portal venous flow volume just after reperfusion was significantly greater in Group 1 than Group 2 (307.8 ± 268.8 vs. 176.2 ± 75.0 mL/min/100 g graft weight, respectively; p < 0.05). Post-transplant infectious complications including ascites infection developed more frequently within the first post-transplant month in Group 1. Massive ascites was significantly associated with early graft loss (p < 0.05). Conclusion:, Post-transplant massive ascites associated with portal over-perfusion into the graft liver can develop in patients with a GRWR over 0.8%. Recipients with post-transplant massive ascites require careful management to prevent infection. [source] Functional significance of hepatic arterial flow reserve in patients with cirrhosisHEPATOLOGY, Issue 2 2003Alexander Zipprich In cirrhosis, hepatic arterial vasodilatation occurs in response to reduced portal venous blood flow. However, although the hepatic arterial flow reserve is high in patients with cirrhosis, its impact on hepatic function is unknown. This study investigated the effect of adenosine-induced hepatic arterial vasodilatation on different markers of liver function. In 20 patients with cirrhosis (Child-Pugh class A/B/C: n = 2/7/11) adenosine (2-30 ,g · min,1 · kg body wt,1) was infused into the hepatic artery and hepatic arterial average peak flow velocities (APV), pulsatility indices (PI), and blood flow volumes (HABF) were measured using digital angiography and intravascular Doppler sonography. Indocyanine green (ICG), lidocaine, and galactose were administered intravenously in doses of 0.5, 1.0, and 500 mg/kg body weight in the presence of adenosine-induced hepatic arterial vasodilatation and, on a separate study day, without adenosine. ICG disappearance, galactose elimination capacity (GEC), and formation of the lidocaine metabolite monoethylglycinxylidide (MEGX) were assessed. Adenosine markedly increased APV and HABF and markedly decreased PI. Serum MEGX concentrations were 63.7 ± 18.2 (median, 62; range, 36-107) and 99.0 ± 46.3 (82.5; 49-198) ng/mL in the absence and presence of adenosine infusion, respectively (P = .001). Adenosine-induced changes in MEGX concentrations were correlated inversely to changes in APV (r = ,0.5, P = .02) and PI (r = ,0.55, P = .01) and were more marked in Child-Pugh class C compared with Child-Pugh class A patients (57.4 ± 49.9 [44; ,14 to 140] vs. 8.4 ± 16.5 [13; ,11 to 35] ng/mL, P < .01). In conclusion, hepatic arterial vasodilatation provides substantial functional benefit in patients with cirrhosis. The effect does not depend directly on hepatic arterial macroperfusion and is observed preferentially in patients with decompensated disease. [source] Automated concentration and recovery of micro-organisms from drinking water using dead-end ultrafiltrationJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2008E.A. Kearns Abstract Aims:, Concentration of pathogens diluted in large volumes of water is necessary for their detection. An automated concentration system placed online in drinking water distribution systems would facilitate detection and mitigate the risk to public health. Methods and Results:, A prototype concentrator based on dead-end hollow fibre ultrafiltration was used to concentrate Bacillus atrophaeus spores directly from tap water. Backflush was used to recover accumulated particulates for analysis. In field tests conducted on a water utility distribution system, 3·2 × 104,1·4 × 106 CFU ml,1 (6·1 × 106,3·0 × 108 CFU) were recovered from the filter when 2·9 × 107,1·0 × 109 CFU were spiked into the system. Per cent recovery ranged from 21% to 68% for flow volumes of 15,21 l. Tests using spore influent levels <10 CFU l,1 (spike < 1000 CFU) yielded 23,40% recovery for volumes >100 l. Conclusions:,B. atrophaeus spores at levels <10 CFU l,1 were concentrated directly from tap water using an automated dead-end hollow-fibre ultrafiltration system. Significance and Impact of the Study:, The prototype concentrator represents a critical step towards an autonomous system that could be installed in drinking water distribution lines or other critical water lines to facilitate monitoring. Recovered samples can be analysed using standard or rapid biosensor methods. [source] | |||||||||||||